This invention relates to the production of livestock feed and more particularly to converting potato waste to a nutritious livestock feed through the growth of yeasts using potato waste as a growth medium.
Persons engaged in raising and marketing livestock are continually searching for a high-quality, economical livestock feed since the cost of feed represents a substantial portion of the cost of bringing an animal to market. The most cost effective feeds result from the conversion of a potential waste product to a feed product. Potato waste from plants processing sweet potatoes or producing potato flakes, granules, french fries or potato chips is a waste product which is too poor in quality to use effectively as animal feed and which is often merely discarded as a slurry. In addition, because such slurries can degrade water quality, the disposal of slurries of potato waste is an expensive matter, subject to federal and state regulations.
What is needed, therefore, is an economical method of converting potato waste having only minimal food value into a nutritious livestock feed.
Mense U.S. Pat. No. 2,738,274 discloses a process for preparing livestock feed by inoculating a substrate with a culture and growing a strain of bacteria on it. The substrate is various finely divided, steamed and cooled vegetable materials, including potatoes. The Mense patent does not disclose or suggest the use of yeast as an inoculant.
Lines U.S. Pat. No. 4,144,132 discloses the production of single-cell protein by using potato processing waste as a growth medium for the yeasts Endomycopsis fibuliger and Candida utilis. However, the yeasts fail to utilize all the starch in the potato waste and cease growing before all the carbohydrates in the potato waste are converted to proteins.
Muller et al. U.S. Pat. No. 4,046,789 discloses a process for separating bakery-type waste products into reusable sugar, starch, protein and fat components by solvent extraction of the fat components and the addition of a starch-hydrolyzing enzyme and a yeast of the Saccharomyces or Candida type to the starch-containing residue. Kanter U.S. Pat. No. 4,894,244 discloses a process utilizing an amyloglucosidase and Candida utilis to produce a product suitable for human consumption. However, each of these processes is intended to produce a human food product, and therefore is conducted under conditions designed to limit any impurities which would render the product unsuitable for human food. Neither of the processes is economically feasible in a process for the production of livestock feed.